Abstract

Introduction: Relatively lower but not higher BMI was associated with left-right skeletal asymmetries in 1)preoperative AIS girls, upper arm length asymmetry (UALA), 2) normal adolescent girls and boys, trunk asymmetry; and 3) normal juvenile girls, skeletal sizes for age associated withUALA.
Objectives: In girls with right thoracic AIS to evaluate the effect of lower and higher BMI upon the relation of curve severity to UALA.
Material and Methods: Data from girls with right thoracic AIS (n=110, preoperative n=77, screened n=33) including Cobb angle, apical vertebral rotation (AVR) and UALA (right minus left, mm), are evaluated by higher (n-57) and lower (n=53) BMI relative to median values (mean BMIs 21.8 and 17.3 respectively, p<0.001).
Results: Mean Cobb angles and UALA are not significantly different between lower and higher BMI. Mean AVR in the lower BMI subset is significantly less than in the higher BMI subset. Cobbangle and AVR each correlate significantly with UALA in girls with lower but not higher BMI.
Conclusion: In accordance with our double neuro-osseous theory for AIS pathogenesis in girls, we postulate that lower BMI girls with presumptively lower circulating leptin levels, have relatively more sympathoactivation causing the skeletal asymmetries and less somatotropic secretions. From previous findings of younger preoperative girls with higher BMI showing early skeletal overgrowth, such girls may have relatively more somatotropic secretions and less sympathoactivation.
Significance: This putative inverse relation for AIS is in accordance with several medical conditions showingan inverse relationship between sympathoactivation and GH/1GF secretions.